Name Prof. dr. G.J. (Gertjan) Medema Prof. Dr. G.J. (Gertjan) Medema Chief Science Officer/ Principal Microbiologist Gertjan.medema@kwrwater.nl +31 (0)30 606 95 11 Profile Gertjan Medema is chief science officer and principal microbiologist at KWR Watercycle Research Institute (formerly: Kiwa Water Research). He is also parttime chair on Water & Health at Delft University of Technology (Sanitary Engineering). The focus of his research at KWR and TUDelft is the provision of a scientific basis for microbial risk management for the Dutch drinking water utilities and other stakeholders in the water sector. This encompasses: development of methods for detection/typing/source tracking of faecal pathogens in water, soil, aerosols; studying the occurrence of these pathogens in the water cycle (wastewater, surface water, groundwater, drinking water, aerosols); studying the transport of pathogens in water bodies (modelling); studying transport of micro-organisms in the subsurface (bank filtration, infiltration, groundwater abstraction) assessment of the removal of micro-organisms by water treatment processes, both conventional and advanced (membrane filtration, UV, advanced oxidation). incorporating this knowledge into quantitative risk assessment/health impact assessment; advising risk management. As chief science officer he coordinates the joint research program of the Dutch water utilities (BTO) and the research strategy and environment at KWR. Education Ph. D. Microbiology (Utrecht University). Thesis: Cryptosporidium and Giardia: new challenges to the water industry. M.Sc. Microbiology (Leiden University). Majors: microbiology, biotechnology. Work experience Current: Chief Science Officer and principal microbiologist, KWR Watercycle Research Institute (former Kiwa Water Research), The Netherlands. (see above) Part-time chair on Water & Health at Delft University of Technology. 1991 to 1996: Manager Water Microbiology (staff of 8), Laboratory for Water and Food Microbiology, National Institute of Public Health and the Environment, Bilthoven, The Netherlands. Coordination, design, management and reporting of research of the sources, occurrence and fate of pathogens in surface, drinking and recreational water and their health significance. His
research focussed on the occurrence and risk of pathogenic bacteria (Campylobacter, Aeromonas, Plesiomonas), protozoa (Cryptosporidium, Giardia) through drinking water and recreational water. He has also been involved in similar research on viruses. He has been co-responsible for the epidemiological studies on the health effects of bathing in fresh water. 1988 to 1990: Project scientist, Laboratory for Water and Food Microbiology, National Institute of Public Health and the Environment, Bilthoven, The Netherlands. Design, performing and reporting of research of the sources and occurrence of pathogens in drinking water. 1986 to 1988; Project scientist, Department of Technical Microbiology, University of Delft, The Netherlands. Design, performing and reporting of research of the microbial ecology of waste water bacteria. Workrelated additonal functions: Professional activities Member of the IWA and active as chair, website editor and assistant secretary of the specialist group on Health-Related Water Microbiology. Member of the Dutch Health Council Committee on safe bathing water. Member of the WHO working group on microbiology, prepared background documents for the WHO guidelines for drinking water quality on protozoan parasites and microbiological risk assessment and has been involved in the preparation of the second and third revision of these guidelines and in a consultation on the environmental transmission of SARS Coronavirus. Chief editor of Drinking Water engineering and Science. Associate editor of Water Science and Technology. Member of the editorial board of the Journal of Water and Health. Reviewer for J. Water Health, Wat. Sci. Technol., J. Appl. Microbiol, Lett Appl. Microbiol, Water Res., Water Supply, Env. Sci. Technol., J. Env. Engin. Sci. Secretary of the Netherlands Society for Microbiology (1993-1996). Member of the scientific committee and organising committee of the International Conference on Cryptosporidium and Giardia, Amsterdam, 2004 (200 participants), and the IWA Health-related Water Microbiology conferences in Melbourne (2002), Cape Town, (2003), Swansea (2005), Tokyo (2007) and Naxos (2009) (150-250 participants) and many national dedicated workshops and conferences (20-50 participants). Invited as evaluator for the EC, Centre for Water Quality and Treatment, Australia; Health Canada, Canada; Sydney Water, Australia, University of Freiburg, Germany, New South Wales government, Australia. Invited as lecturer in the summer school on Microbial Risk Assessment, Michigan State University & Centre for Advancing Microbial Risk Assessment, USA (2006, 2008, 2009, 2011, 2012). Co-ordinator of a European research project (STREP) on quantitative microbiological risk assessment of drinking water MICRORISK (2002-2006). Participant in international research projects on detection methods for Cryptosporidium and Giardia in water (EU Grant), on UV inactivation of Cryptosporidium (AWWARF, DWI, WSAA, Kiwa), on fate and transport of pathogens in surface water catchments (AWWARF, CRC, UNSW, Kiwa), Member of the expert group on Cryptosporidium research of AWWARF, USA (1997-2000).
Member of the Cryptosporidium research steering committee of the Drinking Water Inspectorate, UK (2000-2004). Member of the Global Water Research Coalition expert group on microbiology. Member of NVvM and Waternetwerk. Ph.D. Committee member (invited opponent) Dr. E.J. Chaggu. (WUR). Sustainable environmental protection using modified pit-latrines. Dr. T. Westrell (Linkoping University, Sweden). Microbial risk assessment and its implications for risk management in urban water systems. Dr. A. Hormann (University of Helsinki, Finland). Assessment of the microbial safety of the drinking water produced from surface water under field conditions. Dr. H.H. Abulreesh (Hull University, England). Waterfowl and the bacteriological quality of amenity ponds. Dr. B. Wols (Delft University of Technology). Computational fluid dynamics in drinking water treatment. Dr. G. Lutterodt (Delft University of Technology/Unesco IHE). Transport of multiple Escherichia coli strains in saturated porous media. Ph.D. supervision P. Smeets. (TUD/CiTG). Quantifying pathogen elimination by drinking water treatment for Quantitative Microbiological Risk Assessment. 2008. W. Hijnen (KWR Watercycle Research Institute). Elimination of microorganisms in water treatment. 2009. Running supervision H. Sales Ortells (TUD/KWR Watercycle Research Institute). Health impact assessment of new urban water concepts. M. Taucer (TUD/HWL). Microbial methods for drinking water research. L. Bachert (TUD/Wetsus). Virus inactivation mechanisms. Lecturing TUD CiTG Health risks from man-made water environments. Public Hygiene and Epidemiology (2009-2012) TUD Biotechnology, Microbiology of Man lecture Drinking water microbiology (2007-2008). Summer school Microbial Risk Assessment (2006, 2008), lectures on risk assessment framework, on data collection and analysis for microbial risk assessment and on risk characterisation. WUR Capita selecta (2006-2009), lectures on pathogens in wastewater and on efficacy of waste water treatment in pathogen removal. PAO Risk management in drinking water (2006, 2008), lecture on Water Safety Plans. PAO Distribution (2005), lecture on microbial risks in drinking water distribution. PAO Effluent reuse (2004), lecture on microbial risks of effluent reuse. Parasitology, Leiden University (1992-1997), lecture on drinking water
microbiology and on bathing water microbiology. Publications in international journals (H-factor 16 (scopus) or 19 (scholar)) Peer-reviewd Sales-Ortells, H., Medema, G. (2012). Screening-level risk assessment of Coxiella burnetii (Q Fever) transmission via aeration of drinking water. Environmental Science and Technology 46(7):4125-4133. Heijnen, L., Medema, G. (2011). Surveillance of influenza A and the pandemic influenza A (H1N1) 2009 in sewage and surface water in the Netherlands. Journal of Water and Health 9(3):434-442. Hornstra, L.M., Smeets, P.W.M.H., Medema, G.J. (2011). Inactivation of bacteriophage MS2 upon exposure to very low concentrations of chlorine dioxide. Water Research 45(4):1847-1855. Smeets, P.W.M.H., Rietveld, L.C., Van Dijk, J.C., Medema, G.J. (2010). Practical applications of quantitative microbial risk assessment (QMRA) for water safety plans. Water Science and Technology 61(6):1561-1568. Van Der Wielen, P.W.J.J., Medema, G. (2010). Unsuitability of quantitative bacteroidales 16S rrna gene assays for discerning fecal contamination of drinking water. Applied and Environmental Microbiology 76(14):4876-4881. Hijnen, W.A.M., Suylen, G.M.H., Bahlman, J.A., Brouwer-Hanzens, A., Medema, G.J. (2010). GAC adsorption filters as barriers for viruses, bacteria and protozoan (oo)cysts in water treatment. Water Research 44(4):1224-1234. Medema, G.J., Teunis, P., Blokker, M., Deere, D., Davison, A., Charles, Ph., Loret, J.F. (2009) Risk assessment of Cryptosporidium in drinking water, World Health Organisation, WHO/HSE/WSH/09.04. Heijnen, L., Medema, G.J. (2009). Method for rapid detection of viable Escherichia coli in water using Real-time NASBA. Water Research 43:3124-3132. Smeets, P.W.H.M., Medema, G.J., van Dijk, J.C., 2009. The Dutch secret: how to provide safe drinking water without chlorine in the Netherlands. Drink. Water Eng. Sci., 2:1-14. Medema, G.J., Smeets, P.W.M.H. (2009). Quantitative risk assessment in the Water Safety Plan: case studies from drinking water practice. Wat. Sci. Technol.: Water Supply, 9(2):127-132. Hijnen, W.A.M., C.H.W. Blokker-Koopmans, L. Heijnen & G.J. Medema, 2009. Survival of Clostridium spores in river water and in sand from a slow sand filter. Wat. Sci. Technol.: Water Supply, 9(6):681-688. Wielen, P.W.J.J., Senden, W., Medema, G.J., 2008. Removal of bacteriophages MS2 and ΦX174 during transport in a sandy anoxic aquifer. Environ. Sci. Technol., 42 (12), 4589 4594. Smeets, P.W.M.H., Y.J. Dullemont, P van Gelder, J.C. van Dijk en G.J. Medema, 2007. Improved methods for modelling drinking water treatment in quantitative microbial risk assessment; a case study of Campylobacter reduction by filtration and ozonation, J. Water Health, 6(3):301-314. van Lieverloo, J.H.M., E.J.M. Blokker en G.J. Medema, 2007. Quantitative microbial risk assessment of distributed drinking water using faecal indicator incidence and concentrations, J. Water Health 5, Suppl. 1, 131-149. Mons, M.N., J.M.L. van der Wielen, E.J.M. Blokker, M.I. Sinclair, K.F.A.M.
Hulshof, F. Dangendorf, P.R. Hunter & G.J. Medema. Estimation of the consumption of cold tap water for microbiological risk assessment: an overview of studies and statistical analysis of data, J. Water Health 5, Suppl. 1, 151-170. van Lieverloo, J.H.M., G.A.M. Mesman, G.L. Bakker, P.K. Baggelaar, A. Hamed, G.J. Medema, 2007. Probability of detecting and quantifying faecal contaminations of drinking water by periodically sampling for E. coli: a simulation study, Water Res., 41, 4299-4308. Oesterholt, F., G. Martijnse, G.J. Medema & D. van der Kooij, 2007, Health risk assessment of non-potable domestic water supplies in the Netherlands, J. Water Supply: Res. Technol. Aqua, 56, 3, 171-179. Medema, G.J., 2007. Prologue, a scientific basis for managing drinking water safety from source to tap, J. Water Health, 5, Suppl1, iii Risebro, H.L., M.F. Doria, Y. Andersson, G.J. Medema, K. Osborn, O. Schlosser & P.R. Hunter, 2007, Fault tree analysis of the causes of waterborne outbreaks, J. Water Health, 5, Suppl. 1, 1-18. Smeets, P.W.M.H., J.C. van Dijk, G. Stanfield, L.C. Rietveld & G.J. Medema, 2007. How can the UK statutory Cryptosporidium monitoring be used for quantitative risk assessment of Cryptosporidium in drinking water? J. Water Health, 5, Suppl. 1, 107-118. Hijnen, W.A.M., Y. J. Dullemont, J.F. Schijven, A.J. Hanzens-Brouwer, M. Rosielle & G.J. Medema, 2007. Removal and fate of Cryptosporidium parvum, Clostridium perfringens and small-sized centric diatoms (Stephanodiscus hantzschii) in slow sand filters, Water Research, 41, 2151-2162. Heijnen, L. & G.J. Medema, 2006. Quantitative detection of E. coli, E. coli O157 and other shiga toxin producing E. coli in water samples using a culture method combined with real-time PCR, J. Water Health, 4, 4, 487-498. van Lieverloo, J.H.M., G.J. Medema & D. van der Kooij, 2006. Risk assessment and risk management of faecal contamination in drinking water distributed without a disinfectant residual, J. Water Supply: Res & Technol Aqua, 55, 1, 25-31. Wielen, P.W.J.J. van der, Blokker, M., Medema, G.J., 2006. Modelling the length of microbiological protection zones around phreatic sandy aquifers in The Netherlands. Wat. Sci. Technol., 54(3):63-69. Hijnen, W.A.M., Beerendonk, E.F., Medema, G.J., 2006. Inactivation credit of UV radiation for viruses, bacteria and protozoan (oo)cysts in water: a review. Water Res. 40:3-22. IJpelaar, G.F., van der Veer, A.J., Medema, G.J., Kruithof, J.C., 2005. Byproduct formation during ultraviolet disinfection of a pretreated surface water. J. Environ. Sci. 4:S51-S56. Hijnen, W.A.M., Brouwer-Hanzens, A.J., Charles, K.J., Medema, G.J., 2005. Transport of MS2 phage, Escherichia coli, Clostridium perfringens, Cryptosporidium parvum, and Giardia intestinalis in a gravel and a sandy soil. Environ. Sci. Technol. 39:7860-7686. Davies, C., Kaucner, C., Altavilla, N., Ashbolt, N., Ferguson, C., Korgh, M., Hijnen, W.A.M., Medema, G.J., Deere, D., 2005. Fate and transport of surface water pathogens in watersheds. Report AWWARF, Denver, USA. Medema, G.J., Wullings, B., Roeleveld, P., van der Kooij, D., 2004. Risk
assessment of Legionella and enteric pathogens in sewage treatment works. Water Supply, 4(2):135-142. pdf Ferguson, C., Medema, G.J., Teunis, P.F.M., Davison, A., Deere, D., 2004. Microbiological Health Criteria for Cryptosporidium. In:R.C.A. Thompson (Ed). Cryptosporidium: From Molecules to Disease. Elsevier Science B.V. pp. 293-299. Hijnen, W.A.M., Baars, E., Bosklopper, T.J.G., Veer, A.J. van der, Meijers, R., Medema, G.J., 2004. Influence of DOC on the inactivation efficiency of ozonation assessed with Clostridium perfringens and a lab scale continuous flow system. Ozone Sci. Engin. 26:465-473. Hijnen, W.A.M., Schijven, J.F., Bonne, P., Visser, A., Medema, G.J. 2004. Elimination of viruses, bacteria an protozoan oocysts by slow sand filtration. Water Sci. Technol., 50:147-154. Hijnen, W.A.M., van der Veer, A.J., Beerendonk, E.F., Medema, G.J., 2004. Increased resistance of environmental anaerobic spores to inactivation by UV. Water Supply, 4(2):55-61. Medema, G.J., Hoogenboezem, W., van der Veer, A.J., Ketelaars, H.A.M., Hijnen, W.A.M., Nobel, P.J., 2003. Quantitative risk assessment of Cryptosporidium in surface water treatment. Water Science & Technology 47: 241 247. Schmoll, O., Gibert, M., Howard, G., Hulsmann, A., Medema, G.J., Schulting, F., Vahala, R., 2003. Risk Based Approaches:The Next Step in the Evolution of the Drinking Water Directive. Position paper for the EU drinking water seminar, October 2003. EU, Brussels. Medema, G.J., Payment, P., Dufour, A., Robertson, W., Waite, M., Hunter, P., Kirby, R., Andersson, Y., 2003. Safe drinking water: an ongoing challenge. In: Assessing microbial safety of drinking water. Improving approaches and methods. OECD and WHO, OECD Publications, Paris, France. Medema GJ, Shaw S, Waite M, Snozzi M, Morreau A, Grabow W., 2003. Catchment characterisation and source water quality. In: Assessing microbial safety of drinking water. Improving approaches and methods. OECD and WHO, OECD Publications, Paris, France. Medema GJ, Stuyfzand P., 2002. Removal of micro-organisms upon basin recharge, deep well injection and river bank filtration in the Netherlands. Int. Symp. On Artificial Recharge 5, Australia. Medema GJ, Schijven JF, 2001. Modelling the sewage discharge and dispersion of Cryptosporidium and Giardia in surface water. Water Research, 35(18):4307-4316. Medema GJ, 2001. Approaches to safe drinking water from surface water international view about the issue. In: Zur Bedeutung mikrobiologischer Belastungen fur die Trinkwasserversorgung aus Talsperren eine Zwischenbilanz. ATT-Schriftenreihe Band 2, Oldenburg-Industriverlag, Munchen, Germany. Hijnen WAM, Bosklopper TGJ, Hofman JAMH, Bosch AD, Medema GJ, 2001. Improvement of the disinfection efficiency of the full-scale ozonation of the River-lake waterworks of Amsterdam Water Supply. Proceedings of the 15 th World Ozone Congress, London, UK. Hijnen WAM, Willemsen-Zwaagstra J, Hiemstra P, Medema GJ, van der Kooij D, 2000. Removal of sulphite-reducing clostridia spores by full-scale water
treatment processes as a surrogate for protozoan (oo)cyst removal. Water Science & Technology, 41(7):165-172. Stanfield G, Carrington E, Albinet F, Compagnon B, Dumoutier N, Hambsch B, Lorthoy A, Medema G, Petzoldt H, de Roubin MR, de Savornin Lohman A, Whitmore T, 2000. An optimised and standardised test to determine the presence of the protozoa Cryptosporidium and Giardia in water. Water Science & Technology, 41(7):103-110. Schijven JF, Medema GJ, Vogelaar AJ, Hassanizadeh SM, 2000. Removal of bacteriophages MS2 and PRD1, spores of Clostridium bifermentans and E.coli by deep well injection, J Contam Hydrol, 44: 301-327. Medema GJ, Hiemstra P, Hijnen WAM, Nobel PJ, van der Kooij D, 2000. Total systems approach to water treatment: multiple barriers for Cryptosporidium and Giardia. Water Supply 18(1): 430 434. Medema GJ, Fricker C, Smith H, 2000. Protozoan parasites: Cryptosporidium, Giardia & Cyclospora. WHO Microbiological Review Document for the Guidelines for Drinking Water Quality, WHO, Geneva, Switzerland. Medema GJ, van Asperen IA van, Havelaar AH, 1998. Assessment of the exposure of swimmers to microbiological contaminants in fresh water. Water Science and Technology, 35(11-12):157-163. Medema GJ, Schets FM, Ketelaars HAM, Boschman G, 1998. Improved detection and vital staining of Cryptosporidium and Giardia with flow cytometry. Water Science and Technology, 38(12):61-65. Medema GJ, Schets FM, Teunis PFM, Havelaar AH, 1998. Sedimentation of free and attached Cryptosporidium oocysts and Giardia cysts in water. Applied and Environmental Microbiology, 64(11):4460-4466. Schijven JF, Hoogenboezem W, Nobel PJ, Medema GJ, Stakelbeek A, 1998. Reduction of FRNA-bacteriophages and faecal indicator bacteria by dune infiltration and estimation of sticking efficiencies. Water Science and Technology 38: 127-131. van Asperen IA, Medema GJ, Borgdorff MW, Sprenger MJW, Havelaar AH, 1998. Risk of gastro-enteritis among triathletes in relation to faecal pollution of fresh waters,. International Journal of Epidemiology, 98 (27): 309-315. van Breemen LWCA, Ketelaars HAM, Hoogenboezem W, Medema GJ, 1998. Storage reservoirs a first barrier for pathogenic micro-organisms. Water Science and Technology, 37(2):253-260. Medema GJ, Bahar M, Schets FM, 1997. Survival of Cryptosporidium parvum, Escherichia coli, faecal enterococci and Clostridium perfringens in river water. Influence of temperature and autochthonous micro-organisms. Water Science and Technology, 35(11-12):249-252. Teunis PFM, Medema GJ, Kruidenier L. Havelaar AH, 1997. Assessment of the risk of infection by Cryptosporidium and Giardia in drinking water from a surface water source. Water Research, 31(6):1333-1346. Steerenberg PA, van Asperen IA, van Nieuw Amerongen A, Bieuwenga J, Mol D, Medema GJ, 1997. Salivary levels of immunoglobulin A in triathletes. European Journal of Oral Sciences, 105:305-309. Medema GJ, Teunis PFM, Havelaar AH, Haas CN, 1996. Assessment of the dose-response relationship of Campylobacter jejuni. International Journal of Food Microbiology, 30:101-111.
van Asperen IA, Mank T, Medema GJ, Stijnen C, de Boer AS, Groot JF, ten Ham P, Sluiters JF, Borgdorff MW, 1996. An outbreak of cryptosporidiosis in the Netherlands. Eurosurveillance 1(2):11-12. Ketelaars HAM, Medema GJ, van Breemen LWCA, van der Kooij D, Nobel PJ, Nuhn P, 1995. Occurrence of Cryptosporidium oocysts and Giardia cysts in the River Meuse and removal in the Biesbosch reservoirs. Journal of Water Supply Research and Technology, 44 Suppl. 1:108-111. Medema GJ, Teunis PFM, Gornik V, Havelaar AH, Exner M, 1995. Estimation of the Cryptosporidium infection risk via drinking water. In: Betts et al. (eds.) Protozoan parasites and water. The Royal Society of Chemistry, Cambridge, United Kingdom, pp. 53-56. Medema GJ, van Asperen IA, Klokman-Houweling JM, Nooitgedagt A, van de Laar MJW, Havelaar AH, 1995. The relationship between health effects in triathletes and microbiological quality of fresh water. Water Science and Technology, 31:19-26. Medema GJ, Schets FM, 1993. Occurrence of Plesiomonas shigelloides in surface water: relationship with faecal pollution and trophic state. Zentralblatt Hygiene 194:398-404. Schets FM, Medema GJ, Havelaar AH, 1993. Comparison of Colilert with Dutch standard enumeration methods for Escherichia coli and total coliforms in water. Letters in Applied Microbiology, 17:17-19. Schets FM, Medema GJ, 1993. Prevention of toxicity of metal ions to Aeromonas and other bacteria in drinking water samples using nitrilotriacetic acid (NTA) instead of ethylenediamine tetraacetic acid (EDTA). Letters in Applied Microbiology, 16:75-76. Medema GJ, Schets FM, van de Giessen AW, Havelaar AH, 1992. Lack of colonization of one-day old chicks by viable, non-culturable Campylobacter jejuni. Journal of Applied Bacteriology, 72:512-516. Gruteke P, Medema GJ, Coenen T, Havelaar AH, 1992. Gezondheidsklachten in verband met de zwemwaterkwaliteit bij deelnemers aan een triathlon. Nederlands Tijdschrift voor Geneeskunde, 45:2232-2236. Medema GJ, Wondergem E, van Dijk-Looijaard AM, Havelaar AH, 1991. Effectivity of chlorine dioxide to control Aeromonas in drinking water distribution systems. Water Science & Technology, 24(2):209-212. Havelaar AH, Toorop-Bouma A, Medema GJ, 1990. The occurrence and significance of Aeromonas in water with special reference to mineral water. Riv. Ital. Igiene, 50:349-356. RIVM rapporten Van Wezel, A.P. (1999) Overview of international programmes on the assessment of existing chemicals. RIVM rapport 601503015. Van Wezel, A.P., Traas, T., Polder, M., Posthumus, R., Van Vlaardingen, P., Crommentuijn, T., Van de Plassche, E.J. (1999) Maximum Permissible Concentrations for polychlorinated biphenyls, RIVM rapport 601501006. Van Wezel, A.P., Posthumus, R., Van Vlaardingen, P., Crommentuijn, T., Van de Plassche, E.J. (1999) Maximum Permissible Concentrations for phthalates (dibutylphthalate and di(2-ethyl-hexyl)phthalate), with special emphasis on endocrine disruptive properties. RIVM rapport 601501007
Van Wezel, A.P., Kalf, D., Janus, J. (2000) Selection of substances, deserving policy attention. RIVM rapport 601503017. Sneller, F.E.C., Kalf, D.F., Weltje, L., Van Wezel, A.P. (2000) Maximum Permissible Concentrations and Negligible Concentrations for Rare Earth Elements (REEs). RIVM rapport 601501011 Smit, C.E., Van Wezel, A., Jager, T., Traas, T.P. (2000) Secondary poisoning of cadmium, copper and mercury; implications for the Maximum Permissible Concentrations and Negligible Concentrations in water, sediment and biota. RIVM rapport 601501009. Van Wezel, A.P., Van Vlaardingen, P. (2001) Maximum permissible concentrations and negligible concentrations for antifouling substances. Irgarol 1051, dichlofluanid, ziram, chlorothalonil and TCMTB. RIVM Rapport 601501008. Lijzen, J.P.A., Baars, A.J., Otte, P.F., Rikken, M., Swartjes, F.A., Verbruggen, E.M.J., Van Wezel, A.P. (2001) Technical evaluation of the Intervention Values for Soil/sediment and Groundwater. Human and ecotoxicological risk assessment and derivation of risk limits for soil, aquatic sediment and groundwater. RIVM Rapport 711701023. Verbruggen, E.M.J., Posthumus, R., Van Wezel, A.P. (2001) Ecotoxicological serious risk concentrations for soil, sediments and (groud)water: updated proposals for first series of compounds. RIVM rapport 711701020. Lijzen, J.P.A., Baars, A.J., Verbruggen, E.M.J., Van Wezel, A.P. (2002) Achtergronden bij de herziene risicogrenzen voor bodem, sediment en grondwater in het kader van de "Evaluatie interventiewaarden bodemsanering" RIVM Rapport 711701028. Lijzen, J.P.A., Mesman, M., Aldenberg, T., Mulder, C.D., Otte, P.F., Posthumus, R., Roex, E., Swartjes, F.A., Versluijs, C.W., Van Vlaardingen, P.L.A., Van Wezel, A.P., Van Wijnen, H.J. (2002) Evaluatie onderbouwing BodemGebruiksWaarden. RIVM rapport 711701029. Van Wezel, A.P., De Vries, W., Beek, M. (eds.), (2003) Bodemgebruikswaarden voor landbouw, natuur en waterbodem. RIVM rapport 711701031. Tiktak, A., Van Wezel, A.P., Van Dam, J., Versluijs, K. (2004) Ex ante evaluatie van de Beleidsbrief Bodem. RIVM rapport 500025003. Kuiper, R., Van den Brink, R., Crommentuijn, L., Dirkx, J., Farjon, H., Franken, R., Kragt, F., Lammers, W., De Niet, R., De Nijs, R., Schilderman, C., Van Wezel, A. (2004) Milieu en natuureffecten Nota Ruimte. RIVM rapport 711931009. Van Wezel, A.P., Franken, R.O.G., Van Dam, J.D., Loonen, W., Cleij, P. (2004) Schuiven op zand. Ex ante evaluatie van de reconstructieplannen. RIVM rapport 718401002. Van Wezel, A.P.; Kruitwagen, S. (eds.) (2005) Milieubalans 2005. Milieu en Natuurplanbureau, Rapportnr. 251701066, ISBN: 9069601206. Van Wezel, A.P., Van der Weijden, A.G.G., Van Wijnen, H.J., Mulder, Ch. (2005) Embedding soil quality in land-use planning. RIVM report 500025002. Van Wezel, A.P., Nijland, H.A. (eds.) (2006) Milieuverkenning. Milieu en Natuurplanbureau Van Wezel, A.P., Nijland H.A. (eds.) (2006) Beoordeling Maatregelenpakket Toekomstagenda Milieu. Milieu en Natuurplanbureau
Van Wezel, A.P., Franken, R.O.G., Drissen, E., Versluijs, C.W., Van den Berg, R. (2007) Maatschappelijk kosten-baten analyse van de Nederlandse bodemsaneringsoperatie. MNP rapport 500122002 Professional van der Lugt, K., M. Claassen, T. Beenen, B. Palsma, G. Medema and L. Rietveld 2012 Gezamelijke onderzoeksagenda KWR, STOWA, RIONED, TU Delft en Waternet voor 2012; H2O 45(3):4-5. Medema, G.J., 2011, Watercyclus & waterziektes, WT-Afvalwater 11:7-32. Medema, G., 2011, EHEC en water: een verband?, H2O online 06-06. Medema G., 2011, Geen EHEC in Nederlands Rijnwater, Waterforum online 15-06. Medema, G.J., 2011, Water kan een rol spelen bij uitbraak EHEC in Duitsland, Waterforum online 07-06. Hijnen, W., T. Suylen, J. Bahlman & G.J. Medema, 2011, Actievekoolfiltratie als barrière voor micro-organismen in drinkwaterbereiding. H2O, 44(8):40-43. Medema, G.J., L.C. Rietveld, A. Versteeg & A. van Wezel, 2009, Japan en Nederland wisselen waterkennis uit, H2O, 42(23):6-7. Smeets, P.W.M.H., G.J. Medema, J. Schijven, A.M. de Roda Husman & N. Zantkuijl, 2008, Wereldwijde ervaringen met waterveiligheidsplan, H20, 2008, 41(12):15. Wubbels, G., Schaap, M., Medema, G., 2008. Inactivatie van Campylobacter door UV licht. H 2 O, 41(8):38-39. Medema, G.J., 2007. Definieer toelaatbaar infectierisico drinkwater in context totale volksgezondheid. H 2 O, 40(1):8-9. Hulsmann, A., Medema, G.J., Wezel, A. van, 2007. Betekenis van ontwikkelingen in Brussel voor Nederlandse waterleidingbedrijven. H 2 O, 40(17):14-15. Veerdonk, C. van der, Breimer, A., Medema, G.J. Mul, M., 2006. Vogelgriep geen risico voor drinkwatervoorziening. H 2 O, 39(5):6-7. Hijnen, W.A.M., Medema, G.J., Schijven, J.F., Dullemont, Y., 2006. Langzame zandfiltratie goed biologische veiligheidsbarriere tegen lage kosten, H 2 O, 39(25/26):16-17. Heijnen, L., Wubbels, G., Veenendaal, H., Medema, G.J., 2005. Real-time PCR bevestigt snel en betrouwbaar E. coli kolonies. H 2 O, 38(7):69-71. Medema, G.J., Roda Husman, A.M. de, 2005. Inspectierichtlijn voor analyse microbiologische veiligheid drinkwater. H 2 O, 38(2):9-11. Ton Visser, Wim Hijnen, Yolanda Dullemont, Gertjan Medema (2004). Langzame zandfiltratie als effectieve barrière voor micro-organismen. H 2 O, 37(12):26-29. Visser, A., Hijnen, W.A.M., Dullemont, Y., Medema, G.J., 2004. Langzame zandfiltratie als effectieve barriere tegen micro-organismen. H 2 O, 37(12):26-28. Visser, A., Hijnen, W., Dullemont, Y., Medema, G., 2004. Langzame zandfilters als effectieve barrières voor micro-organismen. H 2 O 37(12):26-28. Beerendonk, E., Medema, G., Wakker, J. Meuleners, M., 2004. Desinfectiecapaciteit van de UV installatie te Roosteren. H 2 O 37(1):27-29. Hijnen, W.A.M., Medema, G.J., Kooij, D. van der, 2003. Kwantificering van de multiple barriers. H 2 O 36(19):24-27.
Bosklopper, K., Hijnen, W., Dullemont, Y., Medema, G.J., 2003. HACCP: risicoanalyse en procesverbetering in de praktijk. H 2 O 36(19):34-37. Medema, G.J., 2003. Nieuwe benadering van ziekteverwekkers in drinkwater. H 2 O 36(19):4. Medema, G.J., Roeleveld, P., Wullings, B. Kooij, D. van der, 2003. Legionella bij RWZI s. H 2 O, 36(8):15-17. Medema, G.J., Lieverloo, J. van., Smeets, P., 2003. Waterveiligheidsplannen speerpunt van WHO voor bescherming drinkwater. H 2 O, 36(19):6-7. Medema, G.J., 2003. SARS veroorzaakt door slechte afvoer rioolwater. H 2 O 36(22):9. IJpelaar, G., Medema, G.J., Kruithof, J., 2002. UV-technologie voor de drinkwaterbereiding: waar staan we nu? H 2 O 35(12):10-11. Medema, G.J., 2002. Zwemmen in je eigen afval. In Gezondheid en Drinkwaterkwaliteit 54e Vakantiecursus in Drinkwatervoorziening. Red. Van Dijk, J.C.. Delft 11 januari, pp. 83-88. Medema, G.J., 2002. Zwemmen in je eigen afval. Afvalwaterwetenschap (1):25-34. Schijven, J., Medema, G, Hassanizadeh, M., 2001. Virusverwijdering door kunstmatige infiltratie: basis voor een veilig ontwerp. H 2 O, 34(6):28-30. Medema, G.J., Dekker, A., Roda Husman, A.M. de, 2001. Verspreiding van mond- en klauwzeer via water? H 2 O, 34(8):4-5. Ruiter, H., Medema, G., 2000. Cryptosporidium en Giardia in zwemwater en infectierisico s voor waterrecreanten. H 2 O, 33(23):28-30. Medema, G., 2000. Zeven doden door E. coli O157 in Canada. H 2 O, 33(16):6. Medema, G, Wullings, B., Heijnen, L., Kooij, D. van der., 2000. Nieuwe methoden voor opsporen Cryptosporidium en Giardia. H 2 O, 33(23):6-7. Medema, G., Ketelaars, H., Nobel, P. Kooij, D. van der., 2000. Cryptosporidium en Giardia in bekkens en beken. H 2 O, 33(23):22-24. Medema, G., Ketelaars, H., Hoogenboezem, W., Schijven, J., 2000. Cryptosporidium en Giardia: het probleem, de oorzaken en de beheersing. H 2 O, 33(23):31-34. Ketelaars, H., Medema, G., Hoogenboezem, W., Ruiter, H., 2000. Cryptosporidium en Giardia in oppervlaktewater en de benodigde verwijderingscapaciteit van de zuiveringen. H 2 O, 33(23):18-22. Hoogenboezem, W., Medema, G.J., Schijven, J., Rijs, G., 2000. Het voorkomen en de bronnen van Cryptosporidium en Giardia in Nederland. H 2 O, 33(23):17-18. Woerdt, D. van der, Heijden, B. van der, Medema, G.J. Sterkenburg, R., 1999. Reinwaterbergingen en RWZI s: (g)een goede combinatie?! H 2 O, 32(14-15):26-29. Hijnen, W.A.M., Nuhn, P., Medema, G.J. Kooij, D. van der., 1999. Verwijdering ziekteverwekkende micro-organismen uit oppervlaktewater bij de drinkwaterbereiding. H 2 O, 32(7):27-31. Hijnen, W., Medema, G., Koreman, E., 1999. Veilig hergebruik van spoelwater. H 2 O, 32(7):25-26. Medema GJ, Ketelaars HAM., 1995. De betekenis van Cryptosporidium en Giardia voor de drinkwatervoorziening. H 2 O, 28:699-704.